✓ Two crowns ✓ Same mass, different density ✓ Vertical slider ✓ Slider works ✓ Slider controls crowns ✓ Slider direction correct ✓ Full slider range ✓ Fall animation ✓ Water displacement ✓ Rising water level ✓ Splash effects ✓ Physics correct ✓ Live mass value ✓ Live volume value ✓ Live density value ✓ Live displaced water ✓ Gilded displaces more ✓ Heureka animation ✓ No external deps ✓ Light bg / dark text ✓ Self-contained HTML
Exceptionally complete implementation with correct physics (ρ_gold=19.30, ρ_silver=7.19, same 1000g mass), genuine SVG water-rise tied to displaced volume, live panel showing all six values, and a full-screen HEUREKA overlay — but splash opacity uses a raw sine that can go negative/flicker, and the bobbing initFloat animation conflicts with the slider transform since both write to the crown group's transform attribute without coordination.
Exceptionally complete implementation with correct physics (ρ_gold=19.30, ρ_silver=7.19, same 1000g mass), genuine SVG water-rise tied to displaced volume, live panel showing all six values, and a full-screen HEUREKA overlay — but splash opacity uses a raw sine that can go negative/flicker, and the bobbing initFloat animation conflicts with the slider transform since both write to the crown group's transform attribute without coordination.